234 research outputs found
Identification of aluminum resistant genotypes among Madeiran regional wheats
Forty-eight genotypes representing wheat diversity from the Island of
Madeira were screened for resistance to aluminum (Al) in nutrient
solution. Seeds of wheat used in the experiments were obtained from
local farmers. The soil pH and content of ionic Al of plots cultivated with wheat were analyzed. The pH of topsoils varied between 3.83 and 6.59.
The amount of ionic Al in soil samples varied between 0.38 and 1.36
cmol Al3 + per kg of soil and was positively correlated with the altitude
of a plot. Eriochrome cyanine staining was used to evaluate the effect of
Al ions on the root elongation. Seventy-two hour exposure of 3-day-old
seedlings to 100 and 200 mM Al in nutrient solution revealed a high
number of Al resistant genotypes among wheat germplasm. After
withdrawal of Al stress, survival and root regrowth was observed in 28
and 23 genotypes screened at 100 and 200 mM Al in nutrient solution,
respectively. Enhanced resistance to Al among Madeiran genotypes was
associated with the amount of ionic Al in the soils. Complexity and
various patterns of responses of tested cultivars to Al stress may suggest
that Madeiran germplasm could be a valuable source of genes controlling
Al resistance for conventional breeding programs and for studies of
molecular bases of mechanisms of Al resistance.Portuguese Foundation for the Science and Technology (FCT, Fundac¸o
para a Cieˆncia e Tecnologia) has sponsored this work, through the Centre of
Biological and Geological Sciences (C.C.B.G.) and the project POCTI/no.
33005/AGR/1999. The authors are also grateful to the Madeiran Centre of
Science and Technology (CITMA) for financial support. Acknowledgements are due to Mr. Roge´rio Correia and Juan Silva for the technical
assistance in conducting the laboratory and fieldwork and to Dr. Andrzej
Aniol for valuable advice during preparation of this manuscript.info:eu-repo/semantics/publishedVersio
Phenotyping the ideotypes of two maize landraces from Madeira archipelago using morpho-agronomic traits and zein pattern
Madeira Archipelago holds specific maize genetic resources whose populations, representing field diversity, were previously classified into four main landrace groups. The ISOPs 0061 and 0070, with common names of “Milho Sequeiro” and “Milho Branco” yellow and white maize, respectively, represent the ideotypes of two of these landraces. These ideotypes have now been analyzed using morpho-agronomic and biochemical traits, to phenotype these landraces. The variation of nine of the ten morpho-agronomic traits was used to separate the landraces ideotypes. However, the seven traits of seed biochemical composition did not allow to segregate the landraces ideotypes. This is not the case of zein pattern, which polymorphism shows to be specific for each ideotype. The original ideotypes populations were regenerated twice under low input conditions. Zein patterns of the original and regenerated accessions were compared, using two electrophoresis techniques. The lab-on-a-chip electrophoresis showed that the standard SDS-PAGE zein pattern with six fractions could be separated into eighteen (ISOP 0061) and twenty (ISOP 0070) protein bands. In contrast, no significant changes were detected in the zein pattern structure of the initial and regenerated accessions of both landraces ideotypes. The chip electrophoresis showed to be a suitable technique to screen and characterize a large number of individuals and accessions of the germplasm collections, due to its reproducibility. In particular, the zein patterns can be used to phenotype ideotypes and establish a formula representing their structure, allowing to detect changes in landrace structure, occurring as a result of gene bank management actions.info:eu-repo/semantics/publishedVersio
Validation of automated artificial intelligence segmentation of optical coherence tomography images
PURPOSE
To benchmark the human and machine performance of spectral-domain (SD) and swept-source (SS) optical coherence tomography (OCT) image segmentation, i.e., pixel-wise classification, for the compartments vitreous, retina, choroid, sclera.
METHODS
A convolutional neural network (CNN) was trained on OCT B-scan images annotated by a senior ground truth expert retina specialist to segment the posterior eye compartments. Independent benchmark data sets (30 SDOCT and 30 SSOCT) were manually segmented by three classes of graders with varying levels of ophthalmic proficiencies. Nine graders contributed to benchmark an additional 60 images in three consecutive runs. Inter-human and intra-human class agreement was measured and compared to the CNN results.
RESULTS
The CNN training data consisted of a total of 6210 manually segmented images derived from 2070 B-scans (1046 SDOCT and 1024 SSOCT; 630 C-Scans). The CNN segmentation revealed a high agreement with all grader groups. For all compartments and groups, the mean Intersection over Union (IOU) score of CNN compartmentalization versus group graders' compartmentalization was higher than the mean score for intra-grader group comparison.
CONCLUSION
The proposed deep learning segmentation algorithm (CNN) for automated eye compartment segmentation in OCT B-scans (SDOCT and SSOCT) is on par with manual segmentations by human graders
Survey on the clinical trial results achieved in Brazil comparing praziquantel and oxamniquine in the treatment of mansoni schistosomiasis
Portuguese propolis: a source of valuable bioactivities
To FEDER/COMPETE/POCI– Operational Competitiveness and Internationalization
Programme, under Project POCI-01-0145-FEDER-006958 and FCT - Portuguese Foundation for Science and
Technology, under the project UID/AGR/04033/2013
KCNV2-associated retinopathy: genotype–phenotype correlations – KCNV2 study group report 3
BACKGROUND/AIMS:
To investigate genotype–phenotype associations in patients withKCNV2retinopathy.
METHODS:
Review of clinical notes, best-corrected visual acuity (BCVA), molecular variants, electroretinography (ERG) and retinal imaging. Subjects were grouped according to the combination ofKCNV2variants—two loss-of-function (TLOF), two missense (TM) or one of each (MLOF)—and parameters were compared.
RESULTS:
Ninety-two patients were included. The mean age of onset (mean±SD) in TLOF (n=55), TM (n=23) and MLOF (n=14) groups was 3.51±0.58, 4.07±2.76 and 5.54±3.38 years, respectively. The mean LogMAR BCVA (±SD) at baseline in TLOF, TM and MLOF groups was 0.89±0.25, 0.67±0.38 and 0.81±0.35 for right, and 0.88±0.26, 0.69±0.33 and 0.78±0.33 for left eyes, respectively. The difference in BCVA between groups at baseline was significant in right (p=0.03) and left eyes (p=0.035). Mean outer nuclear layer thickness (±SD) at baseline in TLOF, MLOF and TM groups was 37.07±15.20 µm, 40.67±12.53 and 40.38±18.67, respectively, which was not significantly different (p=0.85). The mean ellipsoid zone width (EZW) loss (±SD) was 2051 µm (±1318) for patients in the TLOF, and 1314 µm (±965) for MLOF. Only one patient in the TM group had EZW loss at presentation. There was considerable overlap in ERG findings, although the largest DA 10 ERG b-waves were associated with TLOF and the smallest with TM variants.
CONCLUSIONS:
Patients with missense alterations had better BCVA and greater structural integrity. This is important for patient prognostication and counselling, as well as stratification for future gene therapy trials
The Natural History of Leber Congenital Amaurosis and Cone-Rod Dystrophy Associated with Variants in the GUCY2D Gene
OBJECTIVE: To describe the spectrum of Leber congenital amaurosis (LCA) and cone-rod dystrophy (CORD) associated with the GUCY2D gene, and to identify potential clinical endpoints and optimal patient selection for future therapeutic trials. DESIGN: International multicenter retrospective cohort study. SUBJECTS: 82 patients with GUCY2D-associated CORD and LCA from 54 molecularly confirmed families. METHODS: Data were gathered by reviewing medical records for medical history, symptoms, best-corrected visual acuity (BCVA), ophthalmoscopy, visual fields, full-field electroretinography and retinal imaging (fundus photography, spectral-domain optical coherence tomography (SD-OCT), fundus autofluorescence). MAIN OUTCOMES MEASURES: Age of onset, annual decline of visual acuity, estimated visual impairment per age, genotype-phenotype correlations, anatomic characteristics on funduscopy, and multimodal imaging. RESULTS: Fourteen patients with autosomal recessive LCA and 68 with autosomal dominant CORD were included. The median follow-up time was 5.2 years (interquartile range (IQR), 2.6-8.8) for LCA, and 7.2 years (IQR, 2.2-14.2) for CORD. Generally, LCA presented in the first year of life. The BCVA in LCA ranged from no light perception to 1.00 logMAR, and remained relatively stable during follow-up. Imaging for LCA was limited, but showed little to no structural degeneration. In CORD, progressive vision loss started around the second decade of life. The annual decline rate of visual acuity was 0.022 logMAR (P A and the c.2512C>T GUCY2D variant (P = 0.798). At the age of 40 years the probability of being blind or severely visually impaired was 32%. The integrity of the ellipsoid zone (EZ) and external limiting membrane (ELM) on SD-OCT were correlated significantly with BCVA (Spearman's ρ = 0.744, P = 0.001 and ρ = 0.712, P < 0.001, respectively) in CORD. CONCLUSION: LCA due to variants in GUCY2D results in severe congenital visual impairment with relatively intact macular anatomy on funduscopy and available imaging, suggesting a long preservation of photoreceptors. Despite large variability, GUCY2D-associated CORD generally presented during adolescence with a progressive loss of vision and culminated in severe visual impairment during mid to late-adulthood. The integrity of the ELM and EZ may be suitable structural endpoints for therapeutic studies in GUCY2D-associated CORD
Wildfire, deforestation and health in tropical rainforest areas: a scoping review protocol.
INTRODUCTION: Wildfires and deforestation potentially have direct effects on multiple health outcomes as well as indirect consequences for climate change. Tropical rainforest areas are characterised by high rainfall, humidity and temperature, and they are predominantly found in low-income and middle-income countries. This study aims to synthesise the methods, data and health outcomes reported in scientific papers on wildfires and deforestation in these locations. METHODS AND ANALYSIS: We will carry out a scoping review according to the Joanna Briggs Institute's (JBI) manual for scoping reviews and the framework proposed by Arksey and O'Malley, and Levac et al. The search for articles was performed on 18 August 2023, in 16 electronic databases using Medical Subject Headings terms and adaptations for each database from database inception. The search for local studies will be complemented by the manual search in the list of references of the studies selected to compose this review. We screened studies written in English, French, Portuguese and Spanish. We included quantitative studies assessing any human disease outcome, hospitalisation and vital statistics in regions of tropical rainforest. We exclude qualitative studies and quantitative studies whose outcomes do not cover those of interest. The text screening was done by two independent reviewers. Subsequently, we will tabulate the data by the origin of the data source used, the methods and the main findings on health impacts of the extracted data. The results will provide descriptive statistics, along with visual representations in diagrams and tables, complemented by narrative summaries as detailed in the JBI guidelines. ETHICS AND DISSEMINATION: The study does not require an ethical review as it is meta-research and uses published, deidentified secondary data sources. The submission of results for publication in a peer-reviewed journal and presentation at scientific and policymakers' conferences is expected. STUDY REGISTRATION: Open Science Framework (https://osf.io/pnqc7/)
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